Froth flotation



atented Apr. 5, 1932 UNITED STATES L'UDWIG J'- CHRISTMAI TN, OF JERSEYCITY, AND STUART A. FALCONER, OF ELIZABETH, NEW JERSEY, ASSIGNORS 'IOAMERICAN CYANAMID COMPANY, OF NEW YORK, N. Y.,

A CORPORATION OF MAINE FROTH FLO'IATIOIF No Drawing.

This invention relates to the froth flotation of ores and moreparticularly to a process which involves the use of promotors offlotation which are novel and useful.

It is among the objects of this invention to provide a method for theseparation of various minerals from ores containing the same.

More particularly it is amon the objects of this invention to recoversulfi e minerals and oxidized minerals even in very small amounts fromores. By oxidized minerals, we include compounds of heavy metals, suchas lead, zinc, copper, etc., in chemical combination with elements orgroups of elements'other than sulphur, for instance, in theform ofoxides, hydroxides, carbonates and the like. Our invention contemplatesthe use as a promotor in a froth flotation operation, of the reactionproducts of carbon bisulphide and a hydrazine. We generally utilize asubstituted hydrazine, either of the aryl or alkyl t pe.

Although many of the promotors may be successfully used in the flotationof sulfide ores, relatively few are efiective in the flotation ofoxidized minerals. We have discovered that the abpve mentioned class ofcomuse salts thereof, such salts being s pounds, and particularly thedithiocarbazides, are effective not only for sulfide flotation but alsofor oxide flotation. Although the free carbazide may be used, we preferto generally of an alkaline nature. We may a 0 use such reagents incombination with other promotors and with frothers and conditioners.

In order to prepare the compounds constituting the subject matter ofthis invention, we may provide a mixture of 55 parts by weight of phenylhydrazine hydrochloride with parts by weight of carbon disulfide andparts of water. This mixture is cooled in an ice bath and a solution of33 parts of potassium hydroxide in 50 parts of water is slowly addedwith stirring.

After all the potassium hydroxide has been added the mixture is filteredand washed. The filtrate is acidified in an ice bathwith hydrochloricacid producing a white precipitate which is filtered and washed. Theresidue from the reaction mixture is dissolved Iron l 12.9

Application filed January 27, 1930. Serial No. 423,892.

Per cent Copper 5.10

Insoluble; 62.1

A sample was stage crushed to minus 20 mesh. A 1200 gram portion of thisminus 20 mesh ore and 600 cc. of water with 4 lbs. of lime per ton wereground in a steel laboratory'rod mill for a 10 minute period. The abovegrind was transferred to a flotation machine of the sub-aeration typeand diluted to 22% solids. Reagents were added to the machine as follows0.05 lbs. of tphenyldithiocarbazide made up as sodium salt per on 0.03lbs. of gns #5 "steam distilled pine oil per ton A concentrate Wasremoved for 3 minutes In the flotation of oxide ores these reagents arevery effective and the following example illustrates our invention inconnec tion with oxidized lead ore. y

1200 g. of minus ten mesh ore, 1200 g. of water 5.0 lbs. of crude monoammonium phosphate per ton of ore were ground in a steel mesh of thefeed was 60% minus 200 mesh The rod mill charge was transferred to asub-aeration machine and diluted to 22% solids. The reagents are addedto the ma chine and a mineralized froth collected for 20 minutes.

Reagents in lbs. per ton of ore Ammonium dibut '1d1thlophospl1ate..-: 1. 25 1. 25 Phenyl dithiocar nzlde 4. 0 Crudemono-ammonium phosphate- 5. 0 5. 0 Percent lead in heads 26. 6 27. 2Percent lead in concentrntes 38. 2 47. Percent lead in tails 19. 59 4.88 Percent lead in recovery 54. 5 91. 4

The class of compounds used by us may be denoted by the followingstructural formula: i a

s n-nn-nu-d s-me in which R is the aryl or alkyl group, such as phenyl,tolyl, naph'thyl, methyl and the like, or hydrogen; and Me is analkaline metal such as calcium, ammonium, sodium and the like, orhydrogen.

Although we have described our invention setting forth a few specificexamples of the promotors which we have found effective and of ores withwhich we have worked, our invention is broader than the specificdisclosure, in that a large number of compounds may be used inaccordance withour invention and a largevariety of ores maybesuccessfully floated therewith.

Our invention is, therefore, to be construed broadl except as limited bythe claims appende hereto. Y

What we claim is: 1. A method of recovering minerals from ores whichcomprises subjecting an ore'to a froth flotation operation in thepresence of a dithiocarbazide as a promotor. 1

' 2. A method of recovering minerals from ores which comprisessubjecting an ore to a froth flotation operation in the presence of asubstituted dithiocarbazide as a promotor.

3. A method of recovering minerals from ores which comprisessubjectingan ore to a froth flotation operation in the presence of anaryl dithiocarbazide as a promotor.

4. A method of recovering minerals from ores which comprisessubjectingan ore to a froth flotation operation in the presence of aphenyl dithiocarbazide as a promotor.

5. A method of recovering minerals from ores which comprises subjectingan ore to a froth flotation operation in the resence of an alkaline saltof a dithiocarbazi e as a promotor. 1

6. A method of recovering minerals from ores which comprises subjectingan ore to a froth flotation operation in the resence of an alkaline saltof asubstitute dithiocarbazide as a promotor.

froth flotation operation'in the presence of an alkaline salt of an aryldithiocarbazide as a promotor.

8. A method of recovering minerals from ores which comprises subjectingan ore to a froth flotation operation in the presence of an alkalinesalt of a phenyl dithlocarbazide as a promotor.

9. A method of recovering minerals from ores which comprises subjectingan ore to a froth flotation operation in the presence of a promotorhaving the following structural,

formula n-mn-mn--s-m where R is aryl or alkyl or hydrogen and Me isalkaline radical or hydrogen;

In testimony whereof, we have hereunto subscribed-our names this 21stday of J anuary, 1930.

' LUDWIG J. CHRISTMANN.

STUART A. FALCONER. Y i

